Method of and apparatus for locating sights on gun-barrels.



E. T. STEPHENS.

METHOD OF AND APPARATUS FOR LOCATING SIGHTS 0N GUN BARRELS. IAPPLICATION FILED JUNE 12. 1915.

Patented Apr. 25, 1916.

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THE COLUMBIA PLANOGRAPH c0., WASHINGTON, D. c.

ELWYN T. STEPHENS, OF SPRINGFIELD, MASSACHUSETTS.

To all whom it may concern:

Be it known that I, ELwYN T. STEPHENS, a citizen of the United States,residing in Springfield, I-lampden county, Massachusetts, have inventednew and useful Improvements in the Method of and Apparatus for LocatingSights on Gun-Barrels.

In the art of manufacturing rifles it be comes necessary among otherthings to properly locate the sights so that all projectiles will bedirected toward the object upon which the arm is sighted. It is a wellknown fact that it is not practicable and rarely possible to produce arifle barrel wherein the bore is perfectly straight from end to end. Itis also known that the pro jectile follows the direction imparted to itby the first two or three inches of the bore at the muzzle end of thebarrel.

The common term for properly locating the sights on a rifle barrel istargeting and it is to be understood that in using that or right as thecase may term reference is made to properly locating the sights so thatwhen the rear sight is set on the zero mark the bullet will be directedtoward the object sighted upon.

The present method of targeting a gun or locating the sights is toattach the rear sight locating the zero line in the center of the bore,then adjustably mounting the front sight and test the rifle by shootingat a target and moving the front sight to the left require, after eachshot until the desired position is found or in other words, until thecenter of the tan get is pierced by the bullet when sighted, and therifle is then considered to be properly sighted or targeted.

It is commonly found necessary to fire a rifle a considerable number oftimes, thus causing loss of time and ammunition. Now while suchtargeting may properly establish the location of the sights for onedistance, it leaves them improperly located for any other distanceunless it should happen that the bore is absolutely straight and thatthe front and rear sights are both located directly over the axis of thebore. This, however, probably in 99 per cent. of the instances is notpossible, so that as a result the front sight is rarely located over theaxis of the bore of the first two or three inches at the muzzle end, sothat if the rifle be targeted so that the bullet will strike the centerof the bulls-eye at 200 yds. (thisbeing the common distance for militaryor Specification of Letters Patent.

Patented Apr. as, rare.

Application filed June 12. 1915. Serial No. 33,853.

service rifle test) the bullet will not strike the center of thebulls-eye at 300, 400 yards or at any distance other than that for whichit was targeted. It is also common in the locating of the sight on arifle barrel to work from the outside upon the assumption that the boreis parallel in alinement' with the interior of the barrel. It will nowbe seen that if the bullet is controlled in its dlrection by the centerline of the muzzle portion of the bore the gun, in order to be properlysighted, should have the front sight located directly above such centerline and that the zero line of the rear sight should be located inperfect alinement or in the same vertical plane as the center line ofthe muzzle end of the bore and that, therefore, the front sight shouldbe first accurately located directly above such center line and thenecessary location of the zero line of the rear sight ascertained.

When the front and rear sights are 10- cated as above stated the gunwill have been properly targeted so that no firing or change ofadjustment of the sights is required.

As a means for accomplishing the desired result and as one means ofexemplifying my invention I show an apparatus in the accompanyingdrawings wherein the direction of the bore at the muzzle end of thebarrel is ascertained and from this point means are employed to locatethe zero line of the rear sight so that the front sight and the zeroline of the rear sight are in perfect alinement with and in the samevertical plane as the center line of the muzzle end of the bore.

In the accompanying drawings in which like letters of reference indicatelike parts: Figure 1 is-a side elevation of a mechanism devised'by me asone means of carrying out my invention. Fig. 2 is a plan View of thesame; In these two figures the barrel is shown in Fig. 1 and is omittedfrom Fig. 2. In this apparatus I may employ a suitable member comprisinga perfected straight rod which I term the plug and which has a closesliding fit in the muzzle end of the barrel. The portion of this plugwhich projects beyondthe muzzle enters with a close sliding. fit asuitable member projecting vertically therefrom and firmly secured tosaid vertical member is an arm or bar of sufficient length toiextend'to'the rear portion of the arrel: and I prefer that one fa e of such,

perfect alinement with the axis of the plug so that if a marking tool beplaced against this face and moved downwardly against the barrel at thepoint where the rear sight is to be located the location of the zeroline of the rear sight may be ascertained and this being properly markedmay be relied upon in locating the rear sight so that when it is set atthe zero mark it will be in perfect alinement with the axis of themuzzle end of the bore. Explaining now the details of construction ofsaid apparatus as illustrated in the drawings, I prefer that forconveniencein supporting the gun while ascertaining the proper locationof the zero line for the rear 'sight, to provide a supporting mechanismcomprising a suitable base as or having uprights b and a. The uprights 6are provided with adjusting screws d adapted to bear against the side ofthe front sight. It is desirable that the forward sight be permanentlyfixed to the barrel in the same vertical plane and in' alinement withthe axis at the bore at the muzzle end and this sight being fixed inposition, the end of one'of the adjusting screws 03 being brought to aposition which when one side of the sight bears against it, will bringthe center line of the sight in the same plane as the center line oraxis of the'bore, it simply becomes necessary to set up the otheradjusting screw until it bears against the sight on the opposite sideand thus rotate the barrel until both sides ofthe sight are in contactwith the adjusting screws. The barrel will then be properly located withreference to the front sight being in the same vertical plane as theaxis of the bore at arm or bar be in themuzzle end. I prefer that theupright 0 be provided with a laterally movable table e suitablysupported to ride upon anti-friction mechanism which in the drawing Iillustrate as rolls It will now be seen that when thegun is placed inposition, the portion toward the stock resting upon the table 6 maybe-moved laterally with perfect ease.

In Fig. 1 of the drawing I show the barrel marked 9 and a portion of thestock marked II). If the barrel and stock be now placed in position andthe plug 2' inserted through the opening in the block j into the bore ofthe barrel at the muzzle end, the barrel will beimmediately brought intoproper alinement without difliculty because of the lateral movementgrowing out of theemployment of the anti-friction table supportingmechanism. The block j is provided with a lower extension-7c pivotallymounted in the part Z which latter is pivotally mounted in the base a.The block 7' has firmly attached to it, the straight edge extension m,one face of which is in perfect alinement with the axis of the portionof the plug 2' which enters the muzzle end of the bore. e extension onhas mounted upon it a sliding member a, provided with a marking tool 0,capable of vertical movement, so that when the plug is properly insertedat the muzzle end of the barrel, the marking tool 0 may be moved towardthe barrel and the zero mark for the rear sight, and thus mark in theproper position so that it will be in perfect alinement or in the samevertical plane as the axis of the bore at the muzzle end of the barrel.In order to avoid danger of possible friction, and give the extension mperfect freedom of movement, I prefer that its free end be supported ona suitable table, the latter being supported by antifriction mechanismand for this purpose I have shown a table 7) on anti-friction rolls rthe latter being supported by a suitable member s secured to the base a.

In order to adapt the apparatus for guns of different size bore, Iprefer that the block j be provided with a bushing through which theplug passes and it will readily be seen that bushings of the sameexterior diameter but of different interior diameter may be employedwith the same block.

It will readily be seen that the method of ascertaining the location ofthe zero line for the rear sight invented by me, may be employed withoutthe supporting apparatus illustrated in the drawings, although I deemthis, as at present advised, the most convenient apparatus for thepurpose. It will also be seen that very many modifications may be madewithout departure from my invention and I do not wish to be understoodas limiting my claim to the specific mechanism herein explained forascertaining the proper location of the zero line of the rear sight, orin other words, the targeting of a gun barrel.

It will readily be seen that if the gun be sighted or targeted so that abullet will strike the center of the bulls-eye at a 200 yard range, thetargeting being carried out in the old way, that is, by firing the gunand moving the front sight until the bullet strikes the center of thebulls-eye, that unless the bore be perfectly straight from end toend thearm will not be accurate at any range and that while the difference inaccuracy at a distance nearly approximating 200 yards may be said to betrifling and microscopic, it will also be seen that at a range of a mileor more, or at the extreme limit of the carrying capacity of the arm,such inaccuracy is likely to be serious. It will also be seen that theold method of targeting guns comprising firing and adjusting the forwardsight is tedious and expensive and the accuracy as to the range of testis largely dependent upon the personality of the person making the testand that by the old method the targeting relates only to one distance.

So far as known to me, no means has heretofore been provided by whichthe zero or proper mark for the center line of the rear sight has beenscientifically or mechanically ascertained.

Having therefore described my invention, what I claim as new and desireto secure by Letters Patent, is,-

1. The method herein described of targeting gun-barrels, the samecomprising first locating the front sight in the same vertical planewith the axis of the bore at the muzzle end of the barrel and thenlocating the zero line for the rear sight in perfect alinement with thevertical plane of the axis of the bore at the muzzle end of the barrel.

2. The improvement in the art of targeting gun-barrels, comprising firstascertaining the direction of the bore at the muzzle end of the barrel,locating the position of the front sight above and in line with the axisof such bore, ascertaining the position of the vertical plane of theaxis of such bore when extended to the heel portion of the barrel andlocating the zero mark for the rear sight at such point whereby thefront and rear sights are in the same vertical plane with the axis ofthe bore at the muzzle end of the barrel.

3. An apparatus for properly locating the zero mark of the rear sight ofa gun-barrel, comprising a plug adapted to fit and to be inserted in themuzzle end of a gun-barrel and to project therefrom and means supportedby the projecting portion of such plug extending vertically andrearwardly by which the vertical plane of the axis of the bore of themuzzle end may be located on the rear portion of the barrel,substantially as shown.

4. In an apparatus of the class described means to ascertain thealinement of the bore of the muzzle end of a barrel, a member connectedtherewith adapted to support a straight edge and a straight edge memberextending to the rear of and outside of the barrel, one edge of saidstraight-edge being adapted to be arranged in alinement with and in thesame vertical plane with the axis of the bore of the muzzle end of thebarrel and a marking member adapted to mark such line at the rear of thebarrel.

5. In an apparatus for targeting gun barrels, the combination of asuitable support for a gun barrel, a rigid member adapted to enter andfit the bore at the muzzle end of a gun barrel and to extend in directline therefrom, a member mounted, supported by and projecting verticallyfrom the first member, a member rigidly secured to the latter member andadapted to extend to the rear portion of the barrel and anti-frictionmeans carried by the supporting frame for supporting the rear portion ofthe barrel substantially as shown.

6. In an apparatus of the class described, the combination of a suitablesupport for rigidly supporting a gun barrel, means controlled by thewall of the bore at the muzzle end to ascertain the direction of thebore of the muzzle end of the barrel, and means, cooperating therewithand extending therefrom to locate the vertical plane of the axis of suchdirection at the rear portion of the barrel.

7 In an. apparatus of the class described the combination of a memberadapted to en ter and bear against the wall of the bore of a gun barrelat its muzzle end, and means cooperating with and controlled by thefirst mentioned member to locate a point on the exterior of the rearportion of the barrel in the vertical plane of the axis of the bore ofthe muzzle end, substantially as shown.

ELWYN T. STEPHENS.

toptee at thie patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D 0."

